Girder



S4. B. MOORE GIRDE'R Filed July 24, 1925y Oct 2, 1928.

Patented Det. 2, 1928.

i nag-iran stares;

- regain 'STUART B. MORE, OF LA. PORTE, TEXAS.

Application filed .Tilly 24, 1923. Serial No. 653,556.r

the improvements hereinafter described andr claimed make it possible toconstruct a composite steel and concrete girder which will compete incost with wooden structures, even where the latter are untreated.

A further object ofthe invention is to improve the construction ,ofcomposite steel and concrete girders with respect to the distributionofstresses therein, and to render it possible -to erect a structure ofprecast units that will besimilar in all requisites to a pouredstructure without the useof forms.

The invention rests upon'the discovery of means whereby condemned orworn-out railway rails may be employed as chord members in a compositegirder of steel and poured concrete. Old rails, which l find peculiarlysuited to the purpose of my invention, are available in ample quantitieson every railroad. The use of such discarded rails effects a two-foldeconomy, for on the one hand they may be used along the line of therailway, as for example .in constructing trestles instead of beingscrapped and carried to relatively great distances for the purpose ofbeing utilized as scrap; and on the other hand the availability of suchcheap steel reinforcing members for reinforced concrete structures makesit possible for such structures to compete with treated or untreatedwooden structures, whereas heretofore the expense of bringing speciallyprepared reinforcing elements from steel plants to the point of use hasmade reinforced concrete structures far more costly than woodenstructures for trestles and the like.

Railway rails of the usual form are not merely utilizable as chordmembers but are peculiarly suited to the purpose, being of the requisitestrength and of a shape which lendsV contemplates vthe use of speciallyprepared steel members in place of the rails. Moreover, while theimprovements for the reasons indicated above are of special advantage inthe construction of trestles vand bridges for railways, nevertheless myinvention is not limited in itsapplication to railway work but may beapplied whereverreinforcedsteel structures maybe employed.

lnv the accompanying drawings. the pre. ferred form of my improvedgirder is illustrated,

Fig. 1 being a side elevation withthe concrete partly broken away at oneend,

Fig.. 2, atransverse sectional view onfthe line lll-H of Fig. 1, and

lll-lll of Fig. 1. v-

type, .having tread por-tions, designated by the reference numeralspreviouslymentioned, web portions,` 4, 5 and 6, respectively, andflanges, 7, 8 and 9, respectively. These rails are preferably disposedin the manner shown in the drawings, that is to say, two of-the rails, 1and 2, are inverted and serve as compression members, and rail 3 is bentinto the form shown in Fig. 1 and serves as a tension member. rlhe -endsof the rail 8 are brought substantially midway between the adjacent endsof therails 1 and 2 and in this position the three rails are connectedor tied together', preferably by transverse pins 10 having on theirthreaded ends y11 nuts 12, or other means. Preferably fish plates 13will be applied to the web portions of therails 1 and 2 by means ofrivets 1d. The steel frame thus constructed constitutes the chordelements or compression and tension members of a truss, and my inventioncontemplates that metal web members will be general-ly dispensed with inmy` improved truss. Instead of metal web members a monolithic web 15 ofconcrete or other suitable plastic material is produced by means of asuitable form in the usual manner. be observed that the web 15, asillustrated in Fig. 2, conforms in outline to the skeleton frame made upprincipally of the rails 1, 2 and 3. rlhis is the preferred form of myinvention, and l claim as an important feature thereof the relation ofthe rails to the concrete webs, the flanges of the former con-`stituting a substantially unbroken, enveloping loop or loops around theconcrete web in a longitudinal direction, and the upper rails 1 and 2with the pins 10 further conning the web 15 laterally along its topportion.

l/V ith the web constructed in the roughly triangular` cross-sectionalform vshown and Fig. 3, atransverse sectionalview on thel ine Referringto the'. drawings in detail, 1 2 and. 3 designate railway rails. of theusual It will f leo of distortion under load stresses Without such`distortion being opposed by the metal frame orenveloping loops composedof the rails.

Similarly, tension stresses applied to the steel members are opposed bythe compressive ystrength of the concrete Web. For eX- ample, tensionstresses on the rail 3 are ren sisted through the pins l0 by the rails 1and 2 and the Web l5 confined therebetween, not only in a longitudinalbut also in a lateral sense.

Thel distribution of stresses effected by my invention is not to beconfused With reinforced concrete structures in which unconnected steelmembers are imbedded in concrete, or the like. Although in certainrespects my proposed construction functions in a 'manner similar` toreinforced concrete in general, lnevertheless the special functionshereinbefore pointed out result from the relation of the metal frame andconcrete web as described and as hereinafter claimed. It should berecognized that in reinforced concrete the girderresists the stressbecause the steel reinforcement is gripped by the concrete and in mygirder the stresses are transferred to the concrete because a line ofcleavage is developed between the concrete and the steel.

What I claim is:

l. A girder comprising in combination, a concrete Web Aand ianged'compression and tension members joined at their ends, the flanges ofsaid members being disposed outwardly and forming an enveloping looparound the web longitudinally.

2. A girder comprising in combination, a

concrete web, flanged compression members.

overlying the upper longitudinal corners of said Web, a tension memberenveloping said Web along its bottom, there being no metal web members,and means connecting the adjacent ends of the compression members.

The foregoing specification signedy at V'VashingtonD. C., this 23rd dayof July,

STUART B. MOORE.

and tension i

